A tank having a substantially cylindrical jacket and curved intermediate walls welded to the inner surface thereof is known from U.S. patent specification No. 4,789,170. Each intermediate wall is curved in a manner similar to the tank heads and serves as a baffle for preventing excessive surges of a liquid being transported, which surges may result in undesired reaction forces exerted on the transport vehicle, especially when the tank is partially filled.
In the manufacture of conventional tanks of this type, the intermediate walls, which may be baffles or dividing walls, are inserted in the axial direction of the tank and welded to the inner jacket wall before the tank is closed by the tank heads.
There is the problem that the dimensions of the intermediate wall must be somewhat smaller than the clear diameter of the tank, in order that the wall may be inserted into the tank in spite of any non-circular or uneven portions or the inner jacket surface caused in the manufacture.
Since the tank, in this condition, is still open at at least one end and since its cross-section will deform elliptically when the tank lies fiat, inserting a well fitting intermediate wall may even require the tank body to be set to an upright condition, which further complicates the assembly.
In spite of these measures, however, gaps between the outer edge of the intermediate wall and the inner jacket surface of the tank, which render a proper welding difficult or impossible, cannot be avoided.
For stability reasons, the intermediate wall is curved in a manner similar to tank head, particularly where it is intended to provide a complete subdivision of the interior tank space into a plurality of possible pressure-resistant chambers. In this case, a gusset-type area is created between the tank jacket and the peripheral portion of the intermediate wall on the convex side of the latter, where impurities may deposit and corrosion may occur.
It is therefore common to close this gusset area by an overall conical ring which has its larger edge welded to the jacket surface and its smaller edge welded to the convex side of the intermediate wall. Such a ring is advantageous also for pressure reasons when the tank chamber situated on the convex side of the intermediate wall is exposed to an over-pressure.
With intermediate walls having a basket-type curvature, just as with tank heads of this shape, the wall thickness is governed by the knuckle zone as the area exposed to maximum stress. Therefore, in known tanks, the large spherically curved central portion of the intermediate wall is usually excessively heavy.
Another tank is known from German Offenlegungsschrift 3,445,221 in which an intermediate wall of an overall flat design is connected to the inner jacket wall by means of rings of rectangular cross-section. One leg of each ring is fixed the tank and the other to the intermediate wall.